KR19990044638A - Interface for Digital Recorders and Displays - Google Patents

Abstract

The absence of MPEG processing in the consumer digital recorder player 200 may interfere with the on-screen message display of the recorder status. Various methods are disclosed to facilitate on-screen display of such recorder player status messages. The first embodiment returns the reproduced decoded analog video signal 102 to the digital recorder player 200 for insertion of the status message. In a further embodiment, recorder message data is coupled to the digital signal decoders 100, 117, 520 for inclusion with the decoded analog video signal. In another embodiment, the recorder message command CMD is coupled to the decoder 100 to access the recorder specific graphic message. In another embodiment, recorder message data 271 is coupled to the decoder 100 to select a recorder specific graphic message or to display recorder 200 message data when tagged and available. In another embodiment, the digital or analog mode of operation determines the recorder message display position and timing.

Description

Interface for Digital Recorders and Displays

The digital video signal can be processed to form a bit stream with a reduced bit rate. Processing to reduce such bit rates can be performed according to the MPEG compression method, and formatted in MPEG compatible structures such as those used in digital satellite systems such as DSS ^™ or the proposed Grand Alliance or GA terrestrial systems, for example. Can be.

Consumer video recorders may be adapted to provide recordability for both digitally encoded signals and analog signals, for example having a GA or DSS ^™ signal format and processed to be compatible with the MPEG standard. Such a suitable consumer video recorder can be thought of as two electronic systems sharing the recording mechanism, servo and control system in one box. Conventional analog recording methods can be used where the analog luminance signal component frequency modulates the RF carrier and the analog chroma signal component amplitude modulates the second RF signal. Upon reproduction the two modulated signals are demodulated, combined and synthesized to obtain a video display.

During the recording and playback mode of operation, the on-screen display message can indicate the operating status of the video recorder, warning conditions, tape duration, recording time, time code and the like. These on-screen display messages or OSDs can be added to the analog video output signal to provide recorder status information to the user.

Digital recording can be accomplished by using a consumer video recorder as a digital bit stream recorder / player. For example, an MPEG compatible bit stream such as a transport packet can be recorded by reformatting the transport packet to facilitate recording and playback. For example, transport packets can be buffered and error detection and correction data words can be calculated and added. The bit stream to which error correction is added may be formatted into a sync block or a write data block containing a predetermined number of bytes that can be adjusted in each write track. The sync block signal may be coded so that a signal more suitable for digital recording, for example, to remove any DC components or provide a spectral shape of the recorded signal, such modulation may be generated by "code book" type encoding. . In the playback mode, the recording process is effectively reversed, for example, the "code book" encoding is decoded, an error is detected and corrected, and the sync block formatting is removed to restore the bit stream to the same format as the original MPEG. .

In order to reduce the additional cost increase for digital recording and playback, MPEG decoding and encoding are not included in the recorder. Thus, the recorder must process a packet stream such as MPEG without alteration or addition. Therefore, the recorder provides a program delay or time shifting facility. However, while the analog operation is added to the analog output signal, the recorder status and warning and tape timer display may disappear during the digital operation mode. Therefore, the recorder status or the like can be confirmed only by observation of the recorder control panel.

Control and system interconnection between digital signal sources, recorders and monitor displays can be simplified by the use of bidirectional data buses. However, any interconnection added to it of the analog system can result in installation complexity and confusion incomprehensible to the user. There is a need for a simple interconnect method that can provide a coupling between a digital signal source and a display independent of the operating state of the recorder. Such a simple interconnect method should facilitate both analog and digital recorder operation by using the same interconnect system. In addition, during the analog and digital recorder operating modes, recorder status and warning messages need to be displayed to the user.

TECHNICAL FIELD The present invention relates to the field of digital video recording, and more particularly, to coupling between multiple device elements.

1 is a block diagram illustrating a packetized signal source combined for decoding and display.

2 is an exemplary block diagram including various embodiments of the present invention.

3 is an exemplary block diagram illustrating a simple switch incorporating various embodiments of the present invention.

The recorder status, warning and tape timer display disappearing during the digital operation mode for the reasons mentioned above are advantageously provided by the apparatus of the present invention which follows. The digital recording and reproducing apparatus is suitable for operating as a decoder for a video signal compressed in a digital manner. Such apparatus includes a transducer for reproducing a digitally encoded bit stream signal from a recording medium. The playback electronics are coupled to a transducer that processes the digital encoding bit stream signal to produce an output signal bit stream for decoding. The status message generator for generating a display message is responsive to the operation mode of the playback electronic device. The receiving means receives the decoded video signal from the output signal bit stream. An addition means is coupled to the status message generator to receive the display message and add it to the video signal.

1 illustrates a simple consumer digital audio video system. Sources of packetized compressed audio video and control data are shown as combined for decoding and display. Although the receiver, i.e., IRD 100, is shown coupled to receive antenna 50, a modulated signal may be provided from a cable distribution network (not shown). The modulated packetized signal is tuned and demodulated so that the user decision program is separated within the block indicated by packet source 109. The output of the packet source 109 includes a transport packet stream of audio video and control data that is MPEG decoded to generate audio and video signals by the decoder 117. The output from the decoder 117 is combined for monitoring by the display 300. The other source of the packetized signal is shown to be combined in dotted lines as an optional data stream for MPEG decoding by the decoder 117. Thus, decoder 117 can be used to decode transport streams from external packet sources, thereby reducing the cost of these other sources. For example, packet source 75 may represent a computer that forms a packetized output signal. Such a signal may be derived from computer memory or may come from an external source such as a computer network. Such a computer source can play compressed audio video and control data from disk memory. The packet source 75 may also represent a digital video disc player, such as, for example, a DVD format device. Additional sources of transport packets may be provided by a magnetic tape player recorder, ie, packet source 200, which may have a format conforming to, for example, the D-VHS or DVC standard.

2 shows a simple consumer digital video receiver, recorder and display system in an exemplary block diagram. The system uses, for example, an integrated receiver recorder or IRD 100, an audio video monitor display device 300, and a digital video cassette recorder, for example using the D-VHS or DVC format. In the system described above, the digital video display signal is received by the antenna 50 and modulated to an RF carrier. Antenna 50 is coupled to an integrated receiver recorder (IRD) 100. However, the modulated carrier can be delivered to the receiver 100 by a cable distribution system (not shown). The integrated receiver decoder 100 is tuned to the RF carrier frequency to demodulate the MPEG compatible transmission data stream modulation.

The transmission data stream may be decoded to generate analog audio and video signals for immediate monitoring by the audio video display 300. The decoded output signal is represented by signals 101 and 104 coupled between receiver (IRD) 100 and display 300. In view of the cost, it can be shown that the digital recorder 200 does not include MPEG encoding and decoding. Therefore, the digital recorder 200 acts as a bit stream recorder / player to provide the possibility of time shifting or program delay. The degree of complexity required to facilitate the possibility of non-standard speed playback and the omission of MPEG processing impede image playback in SHUTTLE, SLOW MOTION or TRICK-PLAY modes. Thus, in summary, the receiver 100 couples the MPEG compatible packet stream to the digital A / V bus 112 for recording by the recorder 200. Similarly, the packet stream reproduced from the recorder 200 is coupled back to the receiver for MPEG decoding and audio / video generation. A further consequence of omitting MPEG processing from the recorder is that on-screen display messages or status messages in the form of an OSD cannot be combined or added to reproduce a packetized bit stream. Therefore, the state of the recorder is not easily known to the user.

In addition, since the recorder image data is only available during the recording, playback and stop modes, the user may not be aware of the response of the recorder following a control command. For example, the transition from playback to rewind may result in a state known as, for example, playback image switching to an input bit stream, electronics to electronics or E to E, or for example The playback image may disappear and be replaced with a fixed frame derived by IRD, or the moving image may be replaced with a color field. Thus, the user cannot easily relate these visible display effects to the display of the recorder mode response.

The system shown in FIG. 2 represents an interconnect structure of the first invention in which a demodulated transport bit stream is coupled from a receiver (IRD) 100 to a recorder 200 via a bidirectional data bus 112. The transport packet stream is coupled to the data bus via interface port 110 and received by recorder 200 by interface port 210. The interface ports are controlled via a control data stream carried on separate conductors included in data bus 112. The control signal can be derived from the user input by the operation of a control switch (not shown) or by a user generated IR remote control command. For example, the user may select to monitor the digital audio video signal received by the dish antenna 50. The receiver can be selected by contact or via a remote control such as, for example, an IR. Receiver selection can automatically monitor the display selection, ie the display is automatically switched to monitor the MPEG decoded audio video output. The user may select a digital recording mode in which the transport stream received from the IRD 100 via the bus 112 to the recorder is combined to initiate recording. Similarly, the selection of the digital recorder playback mode produces a playback data stream that is combined via bus 112 for decoding by decoder 117 of receiver 100.

The MPEG compatible packetized signal is coupled to recorder 200 and processed for recording by block D. REC. 210. A buffer memory is coupled to block D. REC. 210 to buffer the data stream to form a signal that is more suitable for writing than the packetized data that includes bursts of data having variable period gaps. The buffered data stream is read from the buffer to form a write format sync block that can be encoded into an error detection / correction data word. The sync block format data stream is modulated for recording as described and combined from recording block D. REC. 210 via selection switch A4. Selection switches A4 and A5 are controlled in response to the selected D-VCR operating mode. For example, in FIG. 2, switches A4 and A5 are shown for digital recording and playback with DP digital playback, DR digital recording and switch contacts that combine the data streams to / from the rotating head assembly 250. For analog operation, switches A4 and A5 take alternating positions as indicated by AR analog recording and AP analog playback. D. The sync block format data stream from REC. 210 is coupled to rotating head assembly 250 for writing on magnetic tape.

In the reproduction mode, the recorded sync block format data stream is reproduced from the magnetic tape by the conversion head 251 disposed on the assembly 250. The recovered signal is demodulated by the digital reproduction block D. Rep. 220 to remove any recording channel modulation. The playback signal then relies on error detection and correction by the data words inserted before being recorded. Following error correction, the sync block formatting is removed and recovered so that the bit stream has a packet format substantially the same as that coupled to the recorder for writing. The packet stream from block D. Rep. 220 is coupled to an interface port 210 that couples the packet stream to the bidirectional data bus 112 for MPEG decoding by the decoder 117 in response to the recorder playback mode. .

The integrated receiver decoder 100 decodes the MPEG compatible packet stream to generate both video and audio output signals. For example, FIG. 2 shows video and audio output signals 101 and 102 and component video signal 104 such as, for example, S-Video. However, these digitally reproduced video signals do not have recorder status information typically provided by an on screen display or OSD.

Receiver (IRD) 100, shown in simplified form in FIG. 2, provides full control of the receiver such as, for example, tuning, packet header control demodulation, bus interface control, and selection of packet sources to couple to MPEG decoder 117. A controller (CTRL.) 115. The receiver state or mode of operation may also be indicated by an on screen display message added to the decoded video signal. The controller 115 may construct an on screen display message or may read a predetermined memory message from the memory block MEM. The on-screen display message or OSD is coupled to an OSD inserter or adder such that at block 520 the message is formatted for analog video display and added or combined with the MPEG decoded video signal. The video with the OSD signal is externally coupled through the output amplifier 118 for display by the monitor display 300.

The recorder player 200 in FIG. 2 includes an on-screen display generator (OSD.GEN.) 270 coupled to a control system (CTRL) 205. In response to the signal from the recorder control system 205, the OSD generator 270 generates a status or warning message suitable for operating conditions. These messages are displayed in the block OSD. It is formatted as a video signal for embedding or inclusion in an analog video signal in ADD 275. An analog video signal is coupled from the video selector block SEL. 280 to the on screen display adder 275.

The selector 280 is controlled by the control system 205 and provides selectability among various analog signal sources. For example, switch A1 provides analog input signal selection between the tuner derived signal, baseband analog signal input and MPEG decoded audio video output signal 102. The output from switch A1 is combined for analog recording by block A. REC.

Selector switch A3 of SEL 280 provides a selection of signals to couple to on-screen display adder 275. Switch A3 in FIG. 2 illustrates providing a combination of the present invention to the input of the on-screen display adder 275 the video component of the output signal 102. Thus, for example, the recorder player 200 status message generated during playback is added to the decoded video signal component 102 from the output transport packet stream. Thus, the MPEG decoding reproduction signal digitally derived from the on-screen message addition signal 103 can be viewed by the display 300.

During the analog operation of recorder player 200, switch A3 couples the analog reproduction signal represented by signal VHS to on-screen display adder 275. Therefore, the OSD message is added to the analog reproduction video signal during analog operation. When digital recording is selected, the OSD message can be advantageously added to the decoded analog video signal 102 from the playback bit stream. Therefore, by this advantageous feedback connection, the recorder status message is combined with the video component and output as the analog signal 103.

Switch A2 of selector SEL. 280 advantageously provides a connection that bypasses on-screen display adder 275 and allows output signal 102 to be directly coupled to monitor display 300. Thus, the bypass action of switch A2 allows viewing of the decoded output signal and eliminates the possibility of signal degradation due to adder 275. The bypass path A2 may be selected automatically when the recorder is off, i.e. in STAND BY mode, or when viewing the decoded unrecorded signal " live " bit stream. In order to allow viewing of the decoded unrecorded signal during analog recording, the bypass switch can be operated manually. The advantageous bypass connection prevents unnecessary analog recorder signal processing, for example, via an E / E recorder path that degrades the signal 102 inherently digitally derived. The advantageous bypass action can also be facilitated by mechanical contact, for example, to allow switch A2 to connect receiver (IRD) 100 to monitor display 300 independently of the operating state of recorder 200. have.

On-screen display generator 270 generates a message formatted at specific horizontal and vertical synchronization timings so that the message is displayed at a predetermined location on the display screen when inserted into the video signal. However, when operating in the digital playback mode and using the advantageous feedback connection discussed above, OSD messages can advantageously be generated with different horizontal and vertical synchronization timings than those used during analog recorder operation. This different horizontal and vertical synchronization timing advantageously compensates for the reproduction signal propagation and for example the MPEG decoding delay that occurs at the receiver 100. Thus, the use of different OSD synchronization timings advantageously achieves substantially the same predetermined message position in either analog or digital recorder operation.

The processing and MPEG decoding time delay may amount to a period of a plurality of frames. Multiple frame delays or temporary offsets will generate the OSD message prior to the actual playback visible event. This temporary offset before the recorder OSD message precedes a playback event may result in a delay situation of a user control command and the corresponding playback image effect. The temporary offset may indicate a more obvious problem when displaying the recorded time code signal or recorder tape timer. For example, during tape playback a specific event may be mentioned from the on-screen display of the recorder tape timer or from the OSD of the recorded time code signal. The time mentioned acknowledges the subsequent location of the selected event. However, if the mentioned times are used as an edit point for electronic editing executed between recorders, the resulting edited scene precedes the scene selected during the preliminary review. The effect of the temporary offset between the message and the playback image can be advantageously eliminated by delaying message generation, message communication, OSD display, or by changing the tape timer / time code number or count. In recorder 200, the delay indicated by DLY. 207 can be selected by switches A7 and A8. For example, if the decoded video signal 102 is fed back for inserting a recorder OSD message at block 275, an OSD message command may be generated in response to the controller 205. The message command signal CMD from the controller 205 is coupled to the switch A7 and the delay DLY 207. The switch A7 is controlled in response to the recording mode selected for the recorder 200, ie analog or digital. Switch A7 is displayed in digital mode and selects a delayed version of signal CMD from delay 207. The delayed command signal causes the generation and insertion of an OSD message that substantially matches the decoded video signal. An optional structure uses a switch A8 that can insert a delay 207 into the output from the OSD generator 270. In this structure, the switch A7 is connected to the output of the controller 205. Switch A8 may be used to delay the coupling of signal CMD to bus 112 and IRD 100. The temporary offset between the OSD message and the decoded playback image may be corrected within the receiver 100 by the introduction of a delay, such as indicated by DLY. 116, into a memory accessing signal or a memory output signal. Synchronization of the playback image and the OSD can be accomplished in various ways by, for example, delays using clock data latches, shift registers, monostable multivibrators, and the like. The tape timer or time code OSD can be synchronized with the decoded image during the edit mode preliminary review, for example by arithmetic manipulation of the display number. Thus, the selected image and associated display number can be input to enable electronic editing to be executed. During the analog operation of the recorder 200, the command signal CMD from the controller 205 is not delayed and the switch A7 is directly coupled to the generator 270.

In another embodiment of the present invention, the on-screen display message generated by the recorder 200 can advantageously take advantage of the on-screen display possibilities of the receiver 100. The record derivation message may be coupled to the receiver 100 for inserting the on-screen display into the block OSD 520 of FIG. 2 via the control conductor of the data bus 112. The recorder message data may be formatted by the generator 270 as a text message, to which a tag or label is attached. The tag text message, indicated by signal 271, is coupled to controller 115 of IRD 100 to separate it from other control bus data. Following separation, the text message is combined by the OSD 520 for display formatting and video insertion. The text message is generated in response to the OSD command signal CMD from the controller 205. As mentioned above, the signal CMD may depend on the delay at block 207. However, the text message from block 270 may be delayed at an optional point by inserting switch A7 of delay 207.

In another structure of the present invention, the receiver 100 includes a memory 510 that includes a receiver on screen display message and an OSD message specific to the recorder 200. Recorder specific messages may be accessed in response to a recorder on screen display command signal CMD that may be coupled to the controller 115 via a control bus. In recorder 200, the on-screen display command signal CMD is generated by controller 205 which further determines the message to be generated. Thus, the command signal CMD may be advantageously coupled to the receiver 100 to enable display formatting and accessing of recorder specific graphic messages stored in the memory 510.

In another structure of the present invention, receiver 100 may appropriately select between recorder text messages or receiver graphics messages in response to recorder commands. The choice between the recorder text or IRD graphic message display allows the interconnection of the recorder and receiver to have different features and facilities and have different lifetimes. For example, an older receiver may be connected to a recently manufactured recorder, such that the receiver memory may not contain a preprogrammed graphical message to support the display of recorder on screen messages. Thus, the receiver can display a simple text message generated by the recorder. Conversely, newer receivers can be preprogrammed with the selection of graphical messages for various products of various production years, and these various graphical messages can be displayed instead of the recorder text message. The choice between simple text or graphical messages is facilitated by a tag or label attached to the text message. For example, the tag or label may comprise the command signal CMD for selecting and enabling the required recorder specific message. The label may also provide sufficient data capacity to communicate recorder profile information related to, for example, the date of manufacture, model, version or modification of the recorder and the serial number. When a text message with a tag or label is received by the controller 115, the tag or label is analyzed to cause the selection of the recorder specific graphic message from the IRD memory 510. However, if the receiver memory is not preprogrammed with the particular recorder message or with the message specific to the recorder profile, the tag enables formatting and display of the attached simple text message. As noted above, delay elements may be inserted to compensate for temporal and spatial displacements between the OSD message, text or graphics and the reproduced decoded image.

2 shows three analog signal inputs; Shown is a monitor display 300 having an audio video signal 101, 103 and an audio and component video signal 104 such as, for example, S-video or luminance and coloring components Y, Pr, Pb. In addition, the display 300 may receive audio and video signals through a high frequency signal denoted as RF IN. The signal selector 310 is coupled to video and synchronization processing circuitry (not shown) to generate an image display as is known. Signal selector 310 may be controlled by a user operated switch located on display 300 or by a user initiated remote control command sent via a modulated IR control stream. The three baseband input signals described above may be advantageously selected by automatic control of the selector switch 310. For example, selection of the digital record or playback mode may automatically select an input signal that includes recorder OSD status display information. The recorder status OSD may be generated and initiated as described above. In addition, the provision of a plurality of baseband signal inputs may allow for functional specific device interconnection. For example, direct viewing of the decoded unrecorded signal from IRD 100 may result in the output signal 101 being simultaneously delivered, for example, with the IRD output signal 102 for recorder OSD insertion to form an A / V signal 103. Or by use of the component video signal 103.

3 illustrates the use of a reduced cost display, for example as indicated by display 301. To reduce the display cost, the number of signal inputs may be limited to, for example, an RF input, component video or S-video input, and one audio video signal input. Advantageous selection and bypass possibilities of the selector 280 of FIG. 2 result in the display 301 being monitored and unrecorded material through a single A / V input. However, the display may advantageously utilize the component video signal connection to determine and control display input selection in addition to signal coupling. For example, since the component video signal or the S-VIDEO signal can be taken to provide good display picture quality so that it can be obtained from an NTSC encoded signal, the presence of the component signal coupled to the component signal input may cause Can automatically cause a choice. Thus, when both component and composite signals are coupled to display 301 inputs 1 and 2, respectively, the input controller first has logic to predetermine the selection of the component signal as an input. However, this automatic input selection can prevent the monitoring of signals containing recorder specific on screen display information combined from the recorder 200 of FIG. 2. However, automatic priority input selection may advantageously be used to enable remote controlled selection of the audio and video signal, such as signal 103 at input two, for example. The signal comprising on-screen display information coupled via the recorder 200 is controlled on the display 301 by ingenious control of the component signal 104 by allowing or terminating the output combined signal 104 from the IRD 100. Can be watched. For example, user selection of an unrecorded bit stream, i.e., the received signal, will enable the controller 115 of the receiver 100 to enable the generation or output of the component signal 104, eg, having an S-VIDEO format. Selection of the record image signal for display will cause the controller 115 to generate or terminate the component signal 104. Thus, the controller of the monitor 301 is coupled to the component signal input terminal to sense the absence of the signal 104 via a signal 309, and the input selector 311 is connected from the component input signal 104 on input 1, for example. Switch to an audio video signal 103 on input 2 which is coupled via selector 280 of recorder 200 of FIG.

Claims (4)

In a digital recording and reproducing apparatus 200 suitable for operating as a decoder 117 for a digitally compressed video signal: A transducer 251 for reproducing the digitally encoded bitstream signal from the recording medium; A playback electronic device (220) coupled to the transducer (251) for processing the digitally encoded bitstream signal to produce an output signal bitstream (221) for decoding; A status message generator (270) for generating a display message (272) in response to an operating mode of the device (200); Receiving means (280) for receiving a decoded video signal (102) from the output signal bitstream (221); And adding means (275) coupled to said status message generator (270) for receiving said display message (272) and adding it to said video signal (102). The method according to claim 1, wherein the receiving means 280 has a first mode of operation in which the video signal 102 is coupled for display message addition, and a second for the video signal 102 to bypass the display message addition. A digital recording and reproducing apparatus having an operation mode. The digital device of claim 2, wherein the first operation mode is selected during a power supply operation of the device 200, and the second operation mode is selected when power is not supplied to the device 200. Recording and playback device. 3. The digital recording and reproducing apparatus as claimed in claim 2, further comprising means (A2) for selecting the first and second operating modes of the receiving means.